The process of designing and building a website or application can involve several phases, where different people make contributions at each phase. For instance, in one phase, a designer may plan, develop and lay out the content for the website or application. The website or application layout may take the form of a document containing images, text, backgrounds, fonts and other assets to be incorporated into the website or application. Such a document can have a structured format, such as an Adobe Photoshop® Document, or PSD file, with multiple imaging layers for masks, transparency, text, composite images, colors, and other properties. Subsequently, in another phase, a developer may construct code for the website or application using the layout (e.g., the PSD file) from the designer. Such layout documents can be very large, for example, on the order of three gigabytes. Furthermore, the structure of the layout document may be such that only certain applications, such as Photoshop®, can process the data in the layout document. Additionally, for large or complex files, such processing may require large amounts of processing power and time.